The water-energy-food nexus is promoted as a new approach for research and policy-making. But what does the nexus mean in practice and what kinds of benefits does it bring? In this article we share our experiences with using a nexus approach in Cambodia’s Tonle Sap Lake area. We conclude that water, energy and food security are very closely linked, both in the Tonle Sap and in the transboundary Mekong River Basin generally. The current drive for large-scale hydropower threatens water and food security at both local and national scales. Hence, the nexus provides a relevant starting point for promoting sustainable development in the Mekong. We also identify and discuss two parallel dimensions for the nexus, with one focusing on research and analysis and the other on integrated planning and cross-sectoral collaboration. In our study, the nexus approach was particularly useful in facilitating collaboration and stakeholder engagement. This was because the nexus approach clearly defines the main themes included in the process, and at the same time widens the discussion from mere water resource management into the broader aspects of water, energy and food security.

Forest harvesting operations with heavy machinery can lead to significant soil rutting. Risks of rutting depend on the soil bearing capacity which has considerable spatial and temporal variability. Trafficability prediction is required in the selection of suitable operation sites for a given time window and conditions, and for on-site route optimization during the operation. Integrative tools are necessary to plan and carry out forest operations with minimal negative ecological and economic impacts. This study demonstrates a trafficability prediction framework that utilizes a spatial hydrological model and a wide range of spatial data. Trafficability was approached by producing a rut depth prediction map at a 16 × 16 m grid resolution, based on the outputs of a general linear mixed model developed using field data from Southern Finland, modelled daily soil moisture, spatial forest inventory and topography data, along with field measured rolling resistance and information on the mass transported through the grid cells. Dynamic rut depth prediction maps were produced by accounting for changing weather conditions through hydrological modelling. We also demonstrated a generalization of the rolling resistance coefficient, measured with harvester CAN-bus channel data. Future steps towards a nationwide prediction framework based on continuous data flow, process-based modelling and machine learning are discussed.

The rut formation during forest operations is an undesirable phenomenon. A methodology is being proposed to measure the rut depth distribution of a logging site by photogrammetric point clouds produced by unmanned aerial vehicles (UAV). The methodology includes five processing steps that aim at reducing the noise from the surrounding trees and undergrowth for identifying the trails. A canopy height model is produced to focus the point cloud on the open pathway around the forest machine trail. A triangularized ground model is formed by a point cloud filtering method. The ground model is vectorized using the histogram of directed curvatures (HOC) method to produce an overall ground visualization. Finally, a manual selection of the trails leads to an automated rut depth profile analysis. The bivariate correlation (Pearson’s r) between rut depths measured manually and by UAV photogrammetry is $r=0.67$ . The two-class accuracy a of detecting the rut depth exceeding 20 cm is $a=0.65$ . There is potential for enabling automated large-scale evaluation of the forestry areas by using autonomous drones and the process described.

The recent two decades have witnessed major economic growth and development in South and Southeast Asia. This has led to massive changes and development pressures in the region's transboundary river basins, posing major stress to ecosystems, natural resources and livelihoods. The growing pressure on the existing water resources, close links between water, energy and food as well as the complexity of the problem setting, call for holistic approaches towards managing the shared water resources. Integrated approaches such as Integrated Water Resources Management (IWRM) and Water-Energy-Food nexus (WEF) have been broadly promoted as exemplary holistic processes for guiding water resources management while understanding the broader connections to ecosystems and society. However, through critical examination it is found that they have not yet fully succeeded in providing solutions for transboundary water management: Firstly, they regularly fail to reach and engage other sectors apart from water, the solution potentially remaining limited and water-centric. Secondly, they seek to harmonise the water management policies and practices, while the reality is imbalanced, asymmetrical and dynamic. To better capture this complexity, this dissertation proposes exploring transboundary water management through the framing of wicked problems. Wicked problems are considered to be difficult to solve due to the following characteristics: The problems are ill-defined; Knowledge is incomplete or contradictory; There are a large number of people and opinions involved; The problem creates a heavy economic burden; and These problems are closely interconnected with other ones. Based on the findings of this dissertation, it is argued that characterising water management as a wicked problem – while not providing a concrete set of tools or methods – brings new perspectives to the water-related development challenges in a transboundary context and addresses some of the shortcomings of the integrated approaches. It provides a 'reality check' to the management problems by featuring their complexity in contrast to the more harmonic approaches and by stressing the importance of setting the problem and solution boundaries across relevant thematic, spatial and temporal scales. It further highlights the complexity of the actor space by emphasising that the problem and solution depend on the underlying perspectives, values, interests and the role of power. Despite its inherently pessimistic echo, wicked problems as a concept brings forth an idea that partial and satisfying, instead of optimal or final, solutions need to suffice, as long as they together lead to an overall improvement.Etelä- ja Kaakkois-Aasia ovat läpikäyneet viime vuosikymmenten aikana ripeää talouskasvua ja kehitystä. Tämä on johtanut nopeisiin muutoksiin ja kehityspaineisiin alueen rajavesistöissä, mikä puolestaan kuormittaa ekosysteemejä ja luonnonvaroja sekä luo epävarmuutta perinteisille elinkeinoille. Vesivaroihin kohdistuvat kasvavat paineet, veden, energian ja ruoan väliset läheiset kytkökset sekä koko ongelmakentän kompleksisuus yhdessä peräänkuuluttavat holistisia lähestymistapoja vesivarojen hallintaan. Lähestymistapoja, kuten Kokonaisvaltainen vesivarojen hallinta (IWRM) ja Vesi-energia-ruoka nexus (WEF), on laajasti pidetty esimerkillisinä holistisina prosesseina, jotka ohjaavat vesivarojen hallintaa ja samalla käsittävät laajemmat yhteydet ekosysteemeihin ja yhteiskuntaan. Tästä huolimatta näiden lähestymistapojen kriittinen tarkastelu osoittaa, että ne eivät ole täysin onnistuneet tuomaan ratkaisuja rajavesien hallintaan väitöskirjan tutkimusalueella seuraavista syistä: Ensinnäkin ne eivät ole onnistuneet tavoittamaan vesisektorin ulkopuolisia toimijoita ja kytkeytymään niihin, jolloin ratkaisut saattavat rajoittua ainoastaan vesialaan. Toiseksi, ne pyrkivät harmonisoimaan veteen liittyviä menettelytapoja ja käytäntöjä, vaikka todellisuudessa tätä pyrkimystä hankaloittaa ongelmakentän monimutkaisuus. Ratkaisukentän ollessa täynnä ristiriitaisia näkemyksiä sekä yhtäaikaisia päätöksentekoprosesseja, näiden kokonaisvaltainen hahmottaminen ja yhdenmukaistaminen on todellisuudessa mahdotonta. Väitöskirja ehdottaakin 'ilkeitä ongelmia' kehyksenä rajavesien hallinnan kompleksisuuden ymmärtämiselle ja hahmottamiselle. Ilkeitä ongelmia pidetään vaikeasti ratkaistavina seuraavista syistä: ongelmia on hankala määritellä; tarvittava tieto on puutteellista ja ristiriitaista; osallisia on paljon ja heillä on erilaisia näkemyksiä; ongelmiin liittyy raskas taloudellinen rasite; ja ongelmat ovat läheisesti kytköksissä toisiin vastaaviin. Väitöskirjan löydökset osoittavat, että vesiongelmien määrittäminen ilkeiksi tuo uusia näkökulmia vesivarojen hallinnan haasteisiin sekä yllämainittujen kokonaisvaltaisten lähestymistapojen vajavaisuuksiin. Ensinnäkin tämä muistuttaa ongelmakentän monimutkaisuudesta erona muihin lähestymistapoihin sekä painottaa ongelman ja ratkaisun määrittelyn ja rajaamisen tärkeyttä. Samalla se korostaa toimijakentän monimuotoisuutta ja sitä, että ongelman ja ratkaisun asettelu riippuu näkökulmasta, arvoista, intresseistä sekä vallasta. Huolimatta termin pessimistisestä sävystä ilkeät ongelmat auttavat ymmärtämään, että osaratkaisut, optimaalisten tai lopullisten sijaan, ovat tapa päästä eteenpäin näinkin...

Soil rutting caused by forest operations has negative economic and ecological effects and thus limits for rutting are set by forest laws and sustainability criteria. Extensive data on rut depths are necessary for post-harvest quality control and development of models that link environmental conditions to rut formation. This study explored the use of a Light Detection and Ranging (LiDAR) sensor mounted on a forest harvester and forwarder to measure rut depths in real harvesting conditions in Southern Finland. LiDAR-derived rut depths were compared to manually measured rut depths. The results showed that at 10–20 m spatial resolution, the LiDAR method can provide unbiased estimates of rut depth with root mean square error (RMSE) < 3.5 cm compared to the manual rut depth measurements. The results suggest that a LiDAR sensor mounted on a forest vehicle can in future provide a viable method for the large-scale collection of rut depth data as part of normal forestry operations.